Air-mail pick-up and deposit mechanism



March 21, 1933. L, P. wuLF 1,902,391

AIR NAIL PICK-UP AND DEPOSIT MECHANISM Filed Aug 23, 1930 5 Sheets-Sheet1 I W7 a s um-141 07,

' Louid 11 wulf.

March 21, 1933 P, w L 1,902,391

AIR MAIL PICK-UP AND DEPOSIT MECHANISM Filed Aug. 23, 1930 5Sheets-Sheet 2 attozmq 5 Sheets-Sheet 3 I! In gwuentom Zauz'd' f? ZbizifL. P. WULF AIR MAIL PICK-UP AND DEPOSIT MECHANISM Filed Au 23, 1950March 21, 1933.

March 21, 1933. L. P. WUL.'F 1,902,391

AIR-MAIL PICK-UP AND DEPOSIT MECHANISM Filed Aug. 23, 1930 5Sheets-Sheet 4 March 21 1933.

L. P. W.UI. .F AIR MAIL PICK-UP AND D EPOSI'IKMECHANISM .Filed Aug. 23,19:50

5 Sheefs-Sheet 5 gwuentw Louis 1? wulP.

Patented Mar. 21, 1933 UNITED STATES.

LOUIS P. WULF, OF LOST NATION, IOWA.

AIR-HAIL PICK-U1 AND DEPOSIT MECHANISM Application filed August 23,1930. Serial No. 477,412.

This invention relates to devices whereby airplanes or other aircraftmay pick up mail without alighting and may discharge mail withoutalighting.

One of the objects of the present invention is to provide a constructionof this character in which a mail bag suspended 'by a cable from theaircraft may be guided to an unlatching device which will unlatch themail bag and permit it to drop and which .will simultaneously releaseanother mail bag and engage this second named mail bag with the cable sothat the cable may be drawn up to the-flying machine with the outgoingmail. v

A further object is to provide a construction of this character whichincludes vertical supports, convergent guide members secured to saidsupports, the guide members at their ends terminating in a device forsupporting a mail bag so constructed that as the cable of the aircraftis guided into. the throat of the device, the mail bag support will bedetached and will be engaged with this cable.

A further object is to provide improved" means whereby a mail bag may besupported from the cable and detached therefrom when the cable entersthe throat of the support.

Other objects will appear in the course of the following description. v

My invention is illustrated in the accompanying drawings, wherein Figure1 is a diagrammatic perspective view showing my mail catching anddischarging apparatus for airplanes constructed in accordance with myinvention;

Figure 2 is a longitudinal sectional view of the catching anddischarging device for the mail bags;

Figure 3 is a section on the line of Fig. 2;

Figure 4 is a fragmentary section on thesame plane as Figure 2 but.showing the latch tripped;

Figure 5 is a section on the line 55 of Figure 2;

Figure 6 is a top. plan view partly broken away of the tubular membersand the clip;

Figure '7 is a like view to Figure 6 but -guide wires or elements 14.

showing the clipping member partly withdrawn from the tubular member andthe bolt shot; v

Figure 8 is aside elevation of the structures shown in Figures 6. and 7Figure 9 is an'elevation of the means for supporting the incoming mailbag and showing the mail bag in supported position;

Figure 10 is a like view to Figure 9 but showing the mail bag trippedand dropm K p F igure 11 is a vertical sectional view of the mail bagsupport;

Figure 12 is a section on the line 12--12 of Figure 9;

Figure 13 is a section on the line 1313 of Figure 10, looking in thedirection of the arrows; Y

Figure 14 is a perspective view of the mail 4 bag catcher, the viewbeing somewhat dia-.7

- grammatic in character;

Figures 15, 16 and 17 are diagrammatic views showing the position of theparts at the time when the bag is delivered and the other bag receivedand carried off;

It will be seen from Figures 1 to 14, that the mail bag catching anddelivering device on the ground comprises the uprights 10 which at theirupper ends are curved toward each other as at 11. These uprights will beapproximately forty feet high. Disposed at any desired distance from theuprights 10 there will be uprights 12 held by the guy wires 13 and fromthese uprights extend the The uprights 12 are disposed any desireddistance apart and the guide wires 14 converge toward the gap betweenthe portions 11 of the uprights 10. These uprights 1O may also be heldin an upright position against strain by guy wires. This constructionembodying the guide elements 14' and the tubular arallel elements-16which are next to be escribed, constitutes a ground trap for thecable which supports the mail bag or other package. I

Mounted at the gap between the portions 11 are the horizontally disposedtubular elements 16 as shown in Figure 6 open at their rectly to theends of these tubular elements which are beveled so that a cable will beguided into this throat 17 between the tubuar elements 16. Detachablymounted within the elements 16 at the outer ends thereof is a U-shapedclip 18 having its legs inserted within the tubes 16. This clip 18 isheld within the tubes 16 by frictional engagement, as for instance, bythe plungers 19 urged inward by springs 20, thesesprings and theplungers' being mounted upon housings 21 in turn mounted u on the outerwalls I of the tube 16, the p ungers extending through apertures intheouter walls of the tube and bearing against the legs of the U-shapedclip constituting a coupling member as shown most clearly in Figure 6.The outer end of this clip is rovided with an eye 22 with which themail. ag B is engaged ,by

,means of the cable 23.

Mounted upon the clip 18 isa bolt 24 shown as extending through ahousing 25. A coiled compresslon spring 26 urges this bolt inward. Theinner wall of the tubular member 16 on theside toward this bolt isextended at 27 so that when the clip 18 is in place, this bolt will bear'11 against this extension 27 of this wall an is prevented from beingrojected inward and across the 80 -b' ht .end 0 the clip.-

en this clip s withdrawn partially from the tubular member 16, however,the bolt 24 will pass the extension 27 and the spring will act toproject the bolt directly 35. across the clip. The opposite le of theclip may be provided with a kee r or this bolt or with an a rturefOlLthQ lt. f Disposed in association with the clipjs a eatapult. Thecatapult, of course, com- 40 prises a supurting frame includinglongitu'dmal mem T 28 channeled to constitute opposltely disposed spacedtracks. Operatmg within these tracks is a slide 29 supportmg a seat 30for the mail bag B. This slide 29 has attached wit the cable 31 whichextends to the forward end of the frame ativ'ely Shortformed by themembers 28 and is there carread over a pulley 32, thence around atravelng pulley 33 and thence to theframe 34 to which it attached.Connected to the travehng pulley 33 is a powerful coiled contractalespring or an elastic. cable as for Instance of rubber or any otherretractile member designated generally 35. Where a sprmg s used eitherof rubber or metal, the spnng 15 attached at its end remote from thecable 23 to a part of the frame as at 36. i It will be obvious now thatthe contraction of the spring 35 will act to draw the slide 29 .9 to theforwardv end of the frame butthis slide is held in retracted position bya latch 37, thus holding the'spring 35 in its. expanded condition. Atrip cord 38 is attached to the latch 37, extends through suitableguides and is dletachably connected to the cable 23, as for instance, bya member 38a attached to cord 38 and inserted into the member 23acarried by the cable 23. The two members 23a and 38a are suflicientlyengaged with each other that'they bannot be pulled apart except under.considerable ten sion and will then sepaiate. As soon as the latch isreleased the spring 35 acts to project the bag B in the generaldirection of the cli 18 which has been engaged by a cable. rom the aircraft. Preferably the catapult is mounted as illustrated in Fig. 14 atthe side of the tubular member 16. I do not wish to be limited to this,however.

For the purpose of delivering a mail mg C from a plane and picking upthe bag B,

I designthattlie plane should be provlded with the cable 39, the planebeing provided with means whereby the cable may be wound up or lowered.This means forms no part of my present invention and, therefore, is notillustrated, it being obvious that any means may-be used for thispurpose.

The lower end of the cable 39 passes downward through an opening 40formed in a relatively large head 41 carried on the upper end of ahousing generally designated 42. This housin has a neck 43 at its upperend which imme iately carries the knob 41.

The lower end of the housing is open. The

"housing is relatively thin in cross section asshown in Figure 12. Thecable 39 extends through the aperture 40 and extends to a slide ,43which has sliding fit within the housing 42. This slide islongitudinally slotted at 44 and a pin 45 passes through the housing 42and through this slot. Thus the slide has limited movement within thehousing. Surrounding that ortion of the cable 39 which extends througengages the slide is a coiled com ression s ring 46 which normally urgest e slide ownward. The lower end of the slide on one side is formed witha ertical notch or slot 47 one wall 48 of this notch being rel- Pivotedupon the opposite wall of this slot, that is, upon the ace of the slide43 is a latch 49. The nose of this latch is 7 adapted to extend acrossthe slot 47. The opposite endof the latch projectsout beyond the slideand into the'path of movement of the housing 42. Engaged with this latchis). comprexion spring 50 which is shown as surrounding a rod 51, whichis pivotally engaged at 52 with the latch.

This int of ivotal engagement is normally one si e of the center 53 uponwhich the latch turns. Therefore, this spring will act "to hold thelatch in the position shown in Fi 9'with its nose extending across theslot 47. A stop 54 of any suitable character may be used to; revent anundue depresion o the nose of e latch, beyond the holding point of thelatch. The

the neck 43' mail bag C which is to be delivered from the plane issupported by a short cable. 55 and carries at its end a loop or ring 56through which the nose of the latch is normally disposed. The loop orring 56 and the member 42 with its latch constitutes in effect adetachable coupling between the mail bag or other package and thesupporting cable. When the mail bag C is attached to the carrier on theend of the cable 39,-the nose of the latch is dis osed through this ring56. The weight 0 the mail bag and the weight of the slide, therefore,elongate the contractile spring 46. When the cable 39 isvdropped betweenthe wires 14 and the airship moves forward, the cable 39 will engage theclip 18 and will withdraw this clip as shown in Figure 16. As soon asthe clip is withdrawn, it will slip on down to the cable 39 as shown inFigure 17 and contact with the housing 42, will force the housingdownward, thus causing the housing to release the latch 49, thusretracting the nose of the latch from within the ring 56 and allowingthe mail bag C to drop. -It will thus be seen that I have provided whatis in effect a coupling between the mail bag C and the housing 42, thiscoupling including a latch as one element and the loop or ring 56 as theother element and that this coupling is released as soon as the clip 18engages the housing 42 and forces the housing downward. The continuedmovement of the airplane with the cable 39 will at this time pull uponthe cable 23 which will pull on the cord 38, releasing the latch 37 thusreleasing the catapult which will throw the bag B forward as shown inFig. 4, under the impulse of the spring 35. Then when the cord 38becomes taut, the separable connection formed by the parts 23a and 38a.as shown in Fig. 4 will be separated and the bag B will be carried 01fby the airplane. Of course, any suitable winding means may be usedwithin the airplane for winding up the cable 39 which supportstheincoming and outgoing mail ba i The cable 23 is connected to the clip18 and to the bag B by means of snap hooks or like devices andpreferably the bag will be formed with a pocket within which the cable23 and its snap hooks and a clip 18 may be constantly kept inassociation with the bag. It willbe seen that I have provided a verysimple means whereby a mail bag maybe released from a plane or otheraircraft and.

whereby the outgoing mail bag may be picked up by the aircraft-andwhereby also it is only necessary to be certain that the carrier for theincoming mail bag shall be disposed a sufiicient distance below theguide retraction of the cable 19 and the consequent release of themailbag.

I claim 1. Means for receiving and discharging mail from aircraftincluding a vertical structure formed to provide a gap, parallel tubularmembers disposed in said gap and constituting a neck, horizontallydisposed across the clip, the clip being attached to an outgoing mailbag and a cable depending from the aircraft and havingat its lower endan element larger than the transverse width of the clip whereby as saidelement is pulled taut, the clip will be engaged and retracted from theneck and the bolt will be projected across the clip to thereby attachthe clip to the cable.

2. Means for receiving and discharging mail from aircraft including avertical structure formed to provide a gap, parallel tubular membersdisposed in said gap and constituting a neck, horizontally disposedguides attached to said tubular members and extending rearward therefromin divergent relation to each other, a U-shaped clip having its legsslidably disposed within said tubular guides, means frictionallyretaining said clip in place, a transversely extending normallyretracted-bolt carried by, the clip, and a spring urging said bolt to aposition across the clip, the clip being attached to an outgoing mailbag and a cable depending from the aircraft and having at its lower endan element larger than the transverse width of the clip whereby as saidelement is pulled taut, the clip will be engaged and retracted from theneck, and the bolt will be projected across the clip to thereby attachthe clip to the cable, and a catapult including a seat for the;outgoingmail bag, a trigger for holding said catapult in retracted position, andmeans operatively-connecting the trigger with the clip and causing theretraction of the trigger when the clip is pulled out. I

3. In a mail delivery device for aircraft, a vertical support formed toprovide a gap,

tubular guides mounted in said gap, -a'

U-shaped clip supported by the tubular guides, guide elements convergingtosaid neck to thereby guide a depending cable from the aircraft .intothe bight of said clip, means on the depending cable for engaging saidclip and withdrawing it from the tubular guides and supporting it fromthe cable, acatapult including a mail bag seat, and means for holdingthe catapult in a retracted osition, and means for releasing said holing means when the cable has engaged the clip and withdrawn it from thetubular guides.

4. In a mail delivery device for aircraft, a vertical support formed toprovide a gap,

tubular guides mounted in said gap, a-

U-shaped clip supported by the tubular guides, guide elements convergingto said neck to thereby guide a depending cable from the aircraft intothe bight of said clip, means on the depending cable for engaging saidcli and withdrawing it from the tubular gui es and supporting it fromthe cable, acatapult associated with the vertical members and including-spaced longitudinally extending guides, a slide mounted upon saidguides, a mail bag seat carried by the slide, a spring urging said slideto a forward position, a trigger holding the slide in a rearwardposition, a connection between the mail ba and'said clip, and meansconnected to the exible connection for releasing said trigger to permitthe catapult to project the mail bag.

5. In a mail delivery device for aircraft, a

vertical support formed to provide a gap, tubular guidesmounted in-'s'aid gap, 'a U-shaped clip supported by' the tubular guides, guideelements convergingto said neck to thereby guide 21 depending cable fromthe aircraft into the bight of saidclip,

means on the depending'cable for engaging -spring, a cable'attached atone end of the said clip and withdrawing it from the tubular guides andsupporting it from the cable, a catapult associated with the verticalmembers and including spaced longitudinally extending guides, a slidemounted upon said guides, a mail bag seat carried by the slide, a coiledcontractile-spring fixed atits rear end, a traveling pulley engaged bysaid slide, a fixed pulley at the forward end of the guides throughwhich the cable passes, the cable then passing over the travelingpulley, the extremity of the cable being attached to the forward endsof" the guides,

. wit vertical members.

a trigger holding the slide retracted, a flexible connection between themail bag and said clip, and means connected to the flexible connectionand the trigger whereby the trigger. may be released -when the chp isdrawn from the tubular guides on the 6.' A mail ba'g delivery devicecomprising upright members formed to provide a gap, :1 U-shaped-elementdisposed within the ga and having its legs, extending rearwar ing'adependin cable, a

horizontally disposed guides extending converging toward said gap, theaircraft havhousing' through Y which the cable lidingly passes, thehousing being open at its lower end, a spring surrounding the cable anddisposed in the upper end of the housing, means mthe upper uprightmembers formed to provide a gap,

a- U-shaped element disposed within the ga and having its legs extendingrearward horizontally disposed guides extending convergently toward saidgap, the air craft having a depending cable, a housing through which thecable slidingly passes, the housing being open at its lower end, a

spring surrounding the cable and disposed in-the upper end of thehousing, means in the upper end of the housing against which thespring-bears, a slide disposed within the housing, a latching membercarried in the lower end ofthe slide, the slide havin a recess acrosswhich the latching mem r normally extends, the latching member being'adapted to receive a .loop upon a mail bag to be delivered, the tailendof the latching member extending outward'beyond the slide and in thepath of movement ofasaid housing when the latching member is drawnupward relative to the housing, and a compression spring en aged at itslower end with said slide an at its upper end with the latching memberand acting to yieldingly hold the latching -member in eitherits fullyprojected or fully retracted positions. I

8. A mail bagdeliv'ery device comprising upright members formed toprovide a gap,-

a U-sliaped element disposed in said gap, guides extending convergentlytoward the gap from a distance, a cable depending from the flyingmachine, a housing having a neck and an enlarged head through whichrounding the cable and disposed between the Y I slide and ,the enlargedhead on the housing, the lower end of the slide being formed with alongitudinally extending recess, a.

latch pivoted upon the lower end of theslide and having one end normallyextending across the recess to thereby receive a loopon the mail bag,the tail' end'of the latch extending beyond the slide-and into the pathof movement of the housing when the slide is moved into the housing, andmeans yieldingly retaining the latch in either its fully retracted orits fully projected positlons.

9. Means forreceiving and discharging mail in aircraft includingvertical members 5 having inwardly extending upper extremities spacedfrom each other to form a gap, tubular members mounted at the gap andconstituting a neck, guide wires depending approximately horizontallyfrom a distance and converging toward and connected to the ends of thetubular members, a U-shaped clip having its legs disposed withinthetubular members, means on the tubular members i for frictionallyretaining the clip in place, the clip having a cable attached theretoand attached to the outgoing mail bag, a normally retracted bolt springprojected across the 'clip, means on one of said tubular members forholding said bolt in a retracted position until the clip has been pulledout of the tubular members a depending cable on the aircraft,.and a mailbag tripping and supporting device mounted thereon and including a latchreleasing the last named mail bag automatically when the tripping deviceis engaged with the U-sha ed clip.

10. Means for receiving and ischarging mail from aircraft includingvertical mem; bers having inwardly extending upper ex- .tr'emitiesspaced from each other to form a gap, tubular members mounted at the gapand constituting a neck, guide wires depending approximatelyhorizontally from a distance and converging toward and connected to theends of the tubular members,'a U- shaped clip having its legs disposedwithin the tubular members,-means on-the tubular members forfrictionally retaining the clip in place, the clip having a cableattached 0 thereto and attached to the outgoingmail bag, a normallyretracted bolt spring projected across the clip, means on one of saidtubular members for holding said bolt in a retracted position untiltheclip has been pulled out of the tubular members, a catapult includinga sliding mailbag seat for g" the outgoing mail bag, means acting whenthe clip is withdrawn from the tubular guides to release said catapult,andffineans on o the aircraft for supporting the mail bag including acable, a mail bagsupporting device on the lower end of the cable havinga latch, the mail bag supporting device being wider than the spacebetween the legs of the clip, and means for releasing the incoming -mailbag from the mail bag supporting device automatically when the mail bagsupporting device has engaged said clip and withdrawn it from thetubular member.

11. Means for receiving and discharging mail from aircraft including atrap comprising guides converging toward each other, there being a gapbetween the outer ends of said guides, an element removably disposed insaid gap and to which the outgoing mail bag is attached, a cabledepending from the aircraft, a mail bag sup ort carried by said cableand including a atch operatively engaging the bag, and means acting whenthe mail bag support has engaged said element and withdrawn it from saidguides to release said bag and release the incoming mail bag.

12. A packa e transfer mechanism for airplanes inclu ing a cabledepending from an airplane, means for detachabl coupling \a package tosaid cable, a groun trap having converging members into which the cableis guided, the converging members at their proximate ends being formedto provide a throat, a coupling member connected to an outgoing packageand removably disposed at said throat, the cable being guided into saidcou ling member by the throat, the movement 0' the cable through thethroat detaching the coupling member from the throat, and means actuatedby the downward movement of the coupling member under the weight of theoutgoing package uncoupling the first named package from the cable.

13,- Means for receiving and discharging,

mail from' aircraft including a trailing cable from the aircraft andcarrying a relatively large body thereon, a ground trap including cableguides converging to a relatively narrow throat and a substantiallyU-shaped member detachably disposed in said throat and. between the legsof which U-shaped member the cable is guided by the'throat, the legsbeing less distance apart than the diameter of said body, said memberbeing connected to an outgoing. package, and means for automaticallyclosing the gap between the legs of said U-shaped member when it isdisplaced by said cable through the throat of the guides whereby saidmemher, will be coupled toithe cable.

14. Means for receiving and discharging mail from aircraft including atrailing cable from the aircraft and carrying a relatively large body, aground trap including cable guides converging to a relatively narrowthroat, and a substantially U-shaped member detachably disposed in saidthroat and between the legs of which the cable is guided, the bodycarried by the cable being larger in diameter than the width of thethroat and the U-shaped member, said body constituting I a releasableholding means between the cable and anincoming bag, and means causingthe release of saidholding means after the cable has released theU-shaped member from said guides.

15. Means for receiving and discharging mail from aircraft includingaground trap having cable guides converging to a relatively narrowthroat, thethroat having parallel portions disposed .in a horizontalplane, a horizontally disposed vertically open U-shaped member havingits legs normally disposed in a horizontal plane and supporting the bagwith its bod disposed adjacent to but in. a plane exten ing across thegap defined by said ides, the outgoing package being operative yconnected to "sai, U-shaped member, an. aircraft supported cable, acouplin member carriedaupon the cable and coup g an incoming packagethereto, the coupling member having a releasable latch and being lar erin diameter than the width ,across-vthe egs of the U shaped member, the'U-sha ed member when engaged by said cable an withdrawn from the guidesslipping down the cable under the .Tweight of the incoming package andreleasg said'latch between the incoming package and the cable. j 1

-16. A cable depending from an aircraft and carrying a mail bagsupporting element, there beingcoupling means between the mail bagsupporting element and said cable, including a 100 and a latchingelement normally extendmg through the loop but retractible therefrom, a.ground trap including converging guides defining a gap, and means atsaid gap causing the with rawal of said latch from the loop when thecable has moved out of the gap.

17, In a mail delive device foraircraft,

in which the outgoing ag is provided with means whereby it maybe-engaged and carried away by an airplane, a catapult comprising aslidable seat upon which the be is initially supported, guides in whichsai seat moves, a cable attached to the seat ass ing over a pulley, afixed 511 port to w 'ch one end of the cable isattac ed, a movablepulley engaged in a bight of the cable be-" tween the fixed support andthe first-named pulley, a spring engaged with the movable pulley. andurgmg it in a direction to cause the retraction of the cable, andreleasable means for holding the seat against m0ve-' mentunder theaction of. said spring.

-18 In apackage transfer apparatus for airplanes having a trailingsuspension means deplending from the plane and provided wit pick-upmeans for package-carriers, a trap comprising means for guiding saidpick-up-means, an a package projecting device coactin with said trapadapted.

to beset in operation by the-picking up of the carrier. and comprisingseat, detachable means for latching the seat from movemeritlongitudinally extending ides upon which the seat is mounted for shdingmovement, a cable'attached torthe seat and extendin along said 'des in adirection awayrom said late ing means, a pulley over which the cablepasses, fixed means enghlg'ling the free end of the cable, a movable pey engaging the bight of the cable a contractilesprmg enga g the movable,pulley and urging it in a tion to project the seat along the guides,and means actin to. release said latch upon thepicking up 0 a carrier. b

19. Means for vreceiving and discharging mailfrom aircraft "mcluding astructure formed toprovide a gap, horizontally dis-- posed guides converng.to the g? in said structure, members i osed in sai gap'andconstitutlng a neck,'a shaped clip having sliding enga ement with saidneck members and lattac spring projected bolt carried by one of the legsof the clip and rojectible across the clip, said bolt being he d in aretracted position when the cli is disposed within'the neckmembers, an acable depending from the aircraft and having a member on its end largerin diameter than the width of the clip .whereby when the cablerenterssaid clip and the member engages the 'clip, the clip will be withdrawnfrom the neck members and the bolt automatically projected across theclip behind the cable. V

In testimony whereof I hereunto alfix my e to? an outgoing mail bag, a

